The mechanism of control and the cellular site of interferon synthesis will be studied in cultures of human cells stimulated with polyinosinate-polycytidylate (poly I - poly C). It will be attempted to identify the role of the rough endoplasmic reticulum, smooth endoplasmic reticulum and other cellular organelles in the process of interferon synthesis, secretion and glycosylation. The effect of selective removal of carbohydrate form the interferon glycoprotein on the antiviral activity and physical characteristics of human interferon will be studied. Specific antisera against human interferons will be employed in experiments destined to assess the heterogeneity of interferons derived from different human tissues after stimulation with various viral and non-viral inducers. In particular, we will attempt to determine whether immune-specific interferon is indeed a separate species of interferon. The fate of cell-bound interferon will be analyzed. We will attempt to establish if the interaction of interferon with target cells leads to subtle structural changes on the plasma membrane.